[Zebster]

I'd say it's the EGR valve failing to properly close. The higher than expected EGR flow will then displace fresh air and so the MAF will be lower than expected.

Last week my EGR valve stuck open to the extent that the car became undriveable (had to be recovered to a Volvo dealer where the valve plus the EGR cooler were replaced).

While waiting for the recovery vehicle I read the stored codes using my cheap OBD2 scanner... P2413, P00be, P00bf and P2262.